Photovoltaic power plants employ photovoltaic systems to generate electricity from solar radiation. A photovoltaic system may comprise arrays of solar panels, with each solar panel comprising interconnected solar cells. A solar cell includes P-type and N-type diffusion regions. Solar radiation impinging on the solar cell creates electrons and holes that migrate to the diffusion regions, thereby creating voltage differentials between the diffusion regions. In a backside contact solar cell, both the diffusion regions and the metal contact fingers coupled to them are on the backside of the solar cell. The contact fingers allow an external electrical circuit to be coupled to and be powered by the solar cell.
A photovoltaic inverter converts direct current generated by the solar cells to alternating current suitable for coupling to a power grid at a point of interconnection (POI). The output of the photovoltaic power plant at the POI, such as reactive power, real power, and power factor, are controlled to be within a range of specified values to meet requirements. Embodiments of the present invention pertain to methods and apparatus for controlling the operation of the photovoltaic power plant to control the photovoltaic power plant output at the POI or other delivery node.